Given the age of the RNS 310 and the fact that no new map updates will ever be released for it, you may want to consider replacing the entire head unit rather than investing time and money in finding a V12 SD card. Modern aftermarket units (or used OEM units from later VW models) offer features the RNS 310 never had: live traffic updates, smartphone integration (Apple CarPlay and Android Auto), larger screens, faster processors, and much more detailed maps that are updated regularly over the internet. If you plan to keep the car for several more years, the cost of a modern head unit may be well worth the investment.
The system checks for a specific Card Identification (CID) number unique to official VW SD cards. Standard consumer SD cards will not be recognized by the RNS 310 as valid navigation media without advanced technical workarounds. How to Update Your RNS 310 Navigation 1. Identify Your System rns 310 navigation sd card download